What are the three classes of lipids focused on in Triacylglycerol, phospholipids, and cholesterol.
this module?
What is the precursor of storage lipids and many Phosphatidate.
membrane lipids?
What is the process involved in the generation of Describing the reactions, enzymes, and
cholesterol from acetylCoA? intermediates involved.
How is cholesterol regulated? By describing its regulation.
What is the contribution of cholesterol to the Explaining its contribution.
synthesis of steroid hormones?
How do lipoproteins facilitate the transport and Examining the mechanisms involved.
delivery of cholesterol and triacylglycerol throughout
the body?
What is the precursor of storage lipids and many Phosphatidate.
membrane lipids?
What is the precursor of steroid hormones? Cholesterol.
What is the structure of triacylglycerol and They both have a glycerol backbone to which
phospholipids? several fatty acids are linked.
How many fatty acids are linked to each of the three Three.
carbon atoms of glycerol in triacylglycerol?
How many fatty acids are linked to carbons 1 and 2 Two.
of glycerol in phospholipids?
What is linked to carbon 3 of glycerol in A phosphate group and one of several different
phospholipids? head groups.
What is the common precursor for both classes of Glycerol-3-P.
lipids?
From where is glycerol released when Adipose tissue.
triacylglycerol is degraded in the liver?
,From where is glycerol derived in the liver and other The conversion of dihydroxyacetonephosphate.
tissues?
Where does significant triacylglycerol synthesis In the liver and adipose tissue.
occur?
Where does phospholipid synthesis occur? In all cells since they are major components of
membranes.
What do lipoproteins transport throughout the body? Cholesterol and triacylglycerol.
What is the precursor for both triacylglycerol and Phosphatidate.
phospholipid synthesis?
What is the mechanism of phosphatide synthesis It consists of two consecutive additions of fatty acid
from glycerol-3-P? (using an acyl-CoA derivative) to carbon one and
then to carbon two via ester linkages.
What is the location of the triacylglycerol synthetase It is located on the ER membrane.
complex?
What is the first step in the synthesis of The phosphate group is cleaved off to form
triacylglycerol from phosphatidate? diacylglycerol.
What is the second step in the synthesis of The third fatty acid is linked to carbon 3 to form
triacylglycerol from phosphatidate? triacylglycerol.
What happens to most of the triacylglycerol It is transported to either the muscle to be used as
synthesized in the liver? fuel or to adipose tissue, where it is stored for future
energy needs.
What are the common membrane phospholipids? Phosphatidylcholine, phosphatidylethanolamine,
phosphatidylserine, and phosphatidylinositol.
What is the structure of phospholipids? Phospholipids are amphiphilic molecules, having a
very non-polar region due to the two fatty acid
chains and a highly polar head group.
Where does phospholipid synthesis take place? Phospholipid synthesis takes place in the
endoplasmic reticulum.
, What is the precursor to which an alcohol is linked Phosphatidate is the precursor to which an alcohol
in phospholipid synthesis? is linked in phospholipid synthesis.
What is the activated precursor in lipid synthesis? A derivative of cytidine diphosphate (CDP) is the
activated precursor in lipid synthesis.
What serves as the means to activate sugars in UDP serves as the means to activate sugars in
synthesizing larger carbohydrate molecules such as synthesizing larger carbohydrate molecules such as
glycogen? glycogen.
What may be linked to CDP to activate it in lipid Either the diacylglycerol or the alcohol group may
synthesis? be linked to CDP to activate it, depending on the
reactant.
What is the process of synthesizing Diacylglycerol is activated by linking a CDP
CDP-diacylglycerol using an activated molecule to it, and phosphatidate reacts with CTP
diacylglycerol? to form CDP-diacylglycerol.
How is phosphatidylethanolamine synthesized in In mammals, rather than diacylglycerol being
mammals? activated, the alcohol is activated by linking it to
CDP.
What is the most abundant phospholipid in animals Phosphatidylcholine is the most abundant
and what percentage of membrane mass does it phospholipid in animals and makes up 50% of
make up? membrane mass.
How are phosphatidylcholine levels maintained in Phosphatidylcholine levels are maintained through
animals? two pathways: synthesizing it from an activated
diacylglycerol or an activated alcohol.
Both pathways rely on sufficient dietary choline
being available.
What is the alternative pathway for synthesizing Phosphatidylcholine is synthesized from
phosphatidylcholine? phosphatidylethanolamine by the enzyme
phosphatidylethanolamine methyltransferase, which
methylates the amino group of ethanolamine three
times using S-adenosylmethionine as the methyl
donor.
this module?
What is the precursor of storage lipids and many Phosphatidate.
membrane lipids?
What is the process involved in the generation of Describing the reactions, enzymes, and
cholesterol from acetylCoA? intermediates involved.
How is cholesterol regulated? By describing its regulation.
What is the contribution of cholesterol to the Explaining its contribution.
synthesis of steroid hormones?
How do lipoproteins facilitate the transport and Examining the mechanisms involved.
delivery of cholesterol and triacylglycerol throughout
the body?
What is the precursor of storage lipids and many Phosphatidate.
membrane lipids?
What is the precursor of steroid hormones? Cholesterol.
What is the structure of triacylglycerol and They both have a glycerol backbone to which
phospholipids? several fatty acids are linked.
How many fatty acids are linked to each of the three Three.
carbon atoms of glycerol in triacylglycerol?
How many fatty acids are linked to carbons 1 and 2 Two.
of glycerol in phospholipids?
What is linked to carbon 3 of glycerol in A phosphate group and one of several different
phospholipids? head groups.
What is the common precursor for both classes of Glycerol-3-P.
lipids?
From where is glycerol released when Adipose tissue.
triacylglycerol is degraded in the liver?
,From where is glycerol derived in the liver and other The conversion of dihydroxyacetonephosphate.
tissues?
Where does significant triacylglycerol synthesis In the liver and adipose tissue.
occur?
Where does phospholipid synthesis occur? In all cells since they are major components of
membranes.
What do lipoproteins transport throughout the body? Cholesterol and triacylglycerol.
What is the precursor for both triacylglycerol and Phosphatidate.
phospholipid synthesis?
What is the mechanism of phosphatide synthesis It consists of two consecutive additions of fatty acid
from glycerol-3-P? (using an acyl-CoA derivative) to carbon one and
then to carbon two via ester linkages.
What is the location of the triacylglycerol synthetase It is located on the ER membrane.
complex?
What is the first step in the synthesis of The phosphate group is cleaved off to form
triacylglycerol from phosphatidate? diacylglycerol.
What is the second step in the synthesis of The third fatty acid is linked to carbon 3 to form
triacylglycerol from phosphatidate? triacylglycerol.
What happens to most of the triacylglycerol It is transported to either the muscle to be used as
synthesized in the liver? fuel or to adipose tissue, where it is stored for future
energy needs.
What are the common membrane phospholipids? Phosphatidylcholine, phosphatidylethanolamine,
phosphatidylserine, and phosphatidylinositol.
What is the structure of phospholipids? Phospholipids are amphiphilic molecules, having a
very non-polar region due to the two fatty acid
chains and a highly polar head group.
Where does phospholipid synthesis take place? Phospholipid synthesis takes place in the
endoplasmic reticulum.
, What is the precursor to which an alcohol is linked Phosphatidate is the precursor to which an alcohol
in phospholipid synthesis? is linked in phospholipid synthesis.
What is the activated precursor in lipid synthesis? A derivative of cytidine diphosphate (CDP) is the
activated precursor in lipid synthesis.
What serves as the means to activate sugars in UDP serves as the means to activate sugars in
synthesizing larger carbohydrate molecules such as synthesizing larger carbohydrate molecules such as
glycogen? glycogen.
What may be linked to CDP to activate it in lipid Either the diacylglycerol or the alcohol group may
synthesis? be linked to CDP to activate it, depending on the
reactant.
What is the process of synthesizing Diacylglycerol is activated by linking a CDP
CDP-diacylglycerol using an activated molecule to it, and phosphatidate reacts with CTP
diacylglycerol? to form CDP-diacylglycerol.
How is phosphatidylethanolamine synthesized in In mammals, rather than diacylglycerol being
mammals? activated, the alcohol is activated by linking it to
CDP.
What is the most abundant phospholipid in animals Phosphatidylcholine is the most abundant
and what percentage of membrane mass does it phospholipid in animals and makes up 50% of
make up? membrane mass.
How are phosphatidylcholine levels maintained in Phosphatidylcholine levels are maintained through
animals? two pathways: synthesizing it from an activated
diacylglycerol or an activated alcohol.
Both pathways rely on sufficient dietary choline
being available.
What is the alternative pathway for synthesizing Phosphatidylcholine is synthesized from
phosphatidylcholine? phosphatidylethanolamine by the enzyme
phosphatidylethanolamine methyltransferase, which
methylates the amino group of ethanolamine three
times using S-adenosylmethionine as the methyl
donor.
